JPS6052517A - Manufacture of tough and hard malleable cast iron - Google Patents

Manufacture of tough and hard malleable cast iron

Info

Publication number
JPS6052517A
JPS6052517A JP16079983A JP16079983A JPS6052517A JP S6052517 A JPS6052517 A JP S6052517A JP 16079983 A JP16079983 A JP 16079983A JP 16079983 A JP16079983 A JP 16079983A JP S6052517 A JPS6052517 A JP S6052517A
Authority
JP
Japan
Prior art keywords
casting
cast iron
temp
malleable cast
mold
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP16079983A
Other languages
Japanese (ja)
Inventor
Makoto Suenaga
末永　允
Mitsuru Yano
矢野　満
Yasuoki Ishihara
石原　安興
Kimiteru Otsuka
公輝 大塚
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Proterial Ltd
Original Assignee
Hitachi Metals Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi Metals Ltd filed Critical Hitachi Metals Ltd
Priority to JP16079983A priority Critical patent/JPS6052517A/en
Publication of JPS6052517A publication Critical patent/JPS6052517A/en
Pending legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/18—Hardening; Quenching with or without subsequent tempering
    • C21D1/19—Hardening; Quenching with or without subsequent tempering by interrupted quenching
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D5/00—Heat treatments of cast-iron

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Heat Treatment Of Steel (AREA)
  • Heat Treatment Of Articles (AREA)

Abstract

PURPOSE:To obtain a superior product in shortened working stages without adding expensive elements in large quantities by heat treating a casting immediately after releasing from the mold, and rapidly cooling the casting from a prescribed temp. above the A1 transformation range under specified conditions. CONSTITUTION:Molten metal having the composition of malleable cast iron is charged into a casting mold and solidified. The resulting casting is taken out of the mold, it is heat-treated at once at a prescribed temp. to decompose cementite, and the casting is rapidly cooled from a prescribed temp. above the A1 transformation range. At this time, the casting is rapidly cooled from said temp. at a cooling rate at which pearlitic transformation is not caused, and the cooling is stopped once at a temp. above the Ms point. The temp. is slowly dropped, and after the lapse of a prescribed time, the casting is allowed to cool, or it is rapidly cooled. Thus, tough and hard malleable cast iron having extremely superior mechanical properties such as high strength and toughness is obtd.

Description

【発明の詳細な説明】 本発明は可鍛鋳鉄の製造法に係わり、特に鋳放し後直ち
に熱処理を実施した状態で高強度、高靭性を有する強靭
可鍛鋳鉄の製造法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing malleable cast iron, and particularly to a method for manufacturing strong malleable cast iron that has high strength and high toughness when heat treated immediately after casting.

可鍛鋳鉄において、パーライト地のものでその抗張力は
高々７０　ｋｇ／ａｍ２程度であり、さらに高い抗張力
の材料を得るには基地をベイナイト組織とする必要があ
る。In malleable cast iron, the tensile strength of pearlite base is about 70 kg/am2 at most, and to obtain a material with even higher tensile strength, it is necessary to use a bainite structure as the base.

本発明の目的は、Ｎｊ、Ｍｏなどの高価な元素を多量に
添加せずに、作業工程を短縮し一目製造原価を低減し得
る高強度、高靭性の可鍛鋳鉄を製造する方法を提供する
にある。An object of the present invention is to provide a method for manufacturing malleable cast iron with high strength and high toughness, which can shorten the working process and reduce manufacturing costs at a glance, without adding large amounts of expensive elements such as Nj and Mo. It is in.

本発明は、可鍛鋳鉄組成を有する溶湯を鋳型に注湯し凝
固させた後、鋳造品を鋳型から取出し、直ちに所定の温
度でセメンタイ１〜分解熱処理を実施のした後、Ａ１変
態域以上の所定の温度から急冷する強靭可鍛鋳鉄の製造
法であって、−上記Ａ１変態域以上の温度からパーライ
ト変態を生ぜしめない冷却速度で急冷し、Ｍｓ点以」二
の温度で冷却を一旦停止した後、緩やかに温度を降下さ
せ、所定時間経過後放冷または急冷するものである。In the present invention, after pouring a molten metal having a malleable cast iron composition into a mold and solidifying it, the cast product is taken out from the mold and immediately subjected to cementite 1 to decomposition heat treatment at a predetermined temperature. A method for producing strong malleable cast iron in which the iron is rapidly cooled from a predetermined temperature, comprising: - Rapidly cooling from a temperature above the A1 transformation range at a cooling rate that does not cause pearlite transformation, and temporarily stopping cooling at a temperature of 2' above the Ms point. After that, the temperature is gradually lowered, and after a predetermined period of time, the temperature is allowed to cool or rapidly cooled.

以下本発明の実施例について詳細に説明する。Examples of the present invention will be described in detail below.

実施例　１ （１）化学成分　（重量％） （２）テストピース　φ４０に３００ｍｍ（３）注入温
度　１．．４００ｘ１．４２０°Ｃ（４）熱処理 （５）機械的性質 実施例　１ （１）化学成分　（重量％） （２）ナス１ヘピース　％４０　Ｘ’　３００ｍｍ（３
）注入温度　１．／１００〜１．４２００Ｃ（４）熱処
理 （５）機械的性質 （６）組織、Ｎ０８３は第２図に示す。Example 1 (1) Chemical composition (wt%) (2) Test piece 300 mm in φ40 (3) Injection temperature 1. ．． 400x1.420°C (4) Heat treatment (5) Mechanical properties Example 1 (1) Chemical components (wt%) (2) Eggplant 1 piece %40 X' 300mm (3
) Injection temperature 1. /100 to 1.4200C (4) Heat treatment (5) Mechanical properties (6) Structure, N083 is shown in FIG.

」二連せる通り基地組織はベイナイト組織で、抗張力、
耐力、伸び、衝撃値などきわめて優れた機械的性質を有
する強靭可鍛鋳鉄である。” The base structure is a bainite structure, with tensile strength,
It is a strong malleable cast iron with extremely excellent mechanical properties such as yield strength, elongation, and impact value.

以」二の説明で明らかなように本発明による可鍛鋳鉄の
製造法は、鋳造品をＭｆ型から取出し、直ちに所定の温
度でセメンタイト分解熱処理を実施のした後、Ａ１変態
域以上の所定の温度から急冷する強靭可鍛鋳鉄の製造法
であって、上記Ａ１変態域以上の温度からバーライｌへ
変態を生ぜしぬない冷却速度で急冷し、Ｍｓ点以」二の
温度で冷却を一旦停止した後、緩やかに温度を降下させ
、所定時間経過後放冷または急冷するものである。As is clear from the following explanation, in the method for manufacturing malleable cast iron according to the present invention, the cast product is taken out of the Mf mold, immediately subjected to cementite decomposition heat treatment at a predetermined temperature, and then heated to a predetermined temperature above the A1 transformation range. A method for manufacturing strong malleable cast iron in which the iron is rapidly cooled from a temperature above the A1 transformation range to Barley L at a cooling rate that does not cause transformation, and cooling is temporarily stopped at a temperature below the Ms point. After that, the temperature is gradually lowered, and after a predetermined period of time, the temperature is allowed to cool or rapidly cooled.

従って、Ｕ造品の製作工程の短縮、再加熱の廃止による
製造原価の低減など経済性に優れ、しかも高強度、高靭
性など機械的性質のきわめて優れた強靭可鍛鋳鉄を安定
して製造し得るものである。Therefore, we are able to stably produce strong malleable cast iron that is highly economical, such as shortening the manufacturing process of U-shaped products and reducing manufacturing costs by eliminating reheating, and has extremely excellent mechanical properties such as high strength and toughness. It's something you get.

−ぐ−　−７２− 垢１匣１ 浦ｚｒｉ 　４００-gu- -72- 1 box of dirt 1 urazri 400

Claims (1)

【特許請求の範囲】[Claims] 可鍛鋳鉄組成を有する溶湯を鋳型に注湯し凝固させた後
、鋳造品を鋳型から取出し、直ちに所定の温度でセメン
タイト分解熱処理を実施した後、Ａ１変態域以上の所定
の温度から急冷する強靭可鍛鋳鉄の製造法において、上
記Ａ１変態域以上の温度からパーライト変態を生ゼしぬ
ない冷却速度で急冷し、Ｍｓ点以上の温度で冷却を一旦
停止した後、緩やかに温度を降下させ、所定時間経過後
放冷または急冷することを特徴とする強靭可鍛鋳鉄の製
造法。After pouring molten metal having a malleable cast iron composition into a mold and solidifying it, the cast product is removed from the mold, immediately subjected to cementite decomposition heat treatment at a predetermined temperature, and then rapidly cooled from a predetermined temperature above the A1 transformation region. In the method for manufacturing malleable cast iron, rapidly cooling from a temperature above the A1 transformation region at a cooling rate that does not cause pearlite transformation, once stopping the cooling at a temperature above the Ms point, and then slowly lowering the temperature, A method for manufacturing strong malleable cast iron, which is characterized by allowing it to cool or rapidly cooling it after a predetermined period of time has elapsed.
JP16079983A 1983-09-01 1983-09-01 Manufacture of tough and hard malleable cast iron Pending JPS6052517A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP16079983A JPS6052517A (en) 1983-09-01 1983-09-01 Manufacture of tough and hard malleable cast iron

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP16079983A JPS6052517A (en) 1983-09-01 1983-09-01 Manufacture of tough and hard malleable cast iron

Publications (1)

Publication Number Publication Date
JPS6052517A true JPS6052517A (en) 1985-03-25

Family

ID=15722696

Family Applications (1)

Application Number Title Priority Date Filing Date
JP16079983A Pending JPS6052517A (en) 1983-09-01 1983-09-01 Manufacture of tough and hard malleable cast iron

Country Status (1)

Country Link
JP (1) JPS6052517A (en)

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